A Resource on COVID19

The COVID-19 pandemic has shown a markedly low proportion of cases among children. Age disparities in observed cases could be explained by children having lower susceptibility to infection, lower propensity to show clinical symptoms or both."

https://www.nature.com/articles/s41591-020-0962-9

Any attempt to restart schools and colleges here would be disastrous.

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This is correct from the PoV of the contagion. However, the impact on Indian children who are missing out on any form of structured learning is another matter.

Spaces like this one are directly and indirectly exploring providing viable alternatives using phones and digital devices to help young people keep themselves in learning mode. But we are well aware that the amount of access time is severely limited even for those with access, and for many, access is not yet a meaningful factor.

We lack good data on access for children. Instead, what we have (and, believe it or not, is being circulated in social media as though it is an option) is an advertisement for one mobile phone service provider. It portrays a situation where access is universal, and goes further to portray that online instructional methodologies are tested to work.

It hardly needs to be stated that neither is true. We have very little idea of what works, and for whom. We do know that creating involvement is one positive intervention, but we don’t know how many children, and where, can take advantage.

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I am quite sure that Zero kids at the bottom of the pyramid have any formal learning during the shutdown.
I see several street vendors children tagging along with the parents. Most of the vendors have worn out mobiles in plastic pouches. In casual conversations with them, most have just this one phone with pre paid sims and the lowest available data pack for use in phone banking. None of the children are engaged in any learning now.
Then there is a steady stream of laborers begging for food. The numbers have decreased but still a sizeable number. These folks have their phones disconnected due to no recharge.

It is a pathetic state of affairs.

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Marvi Cheema et al, Keratoconjunctivitis as the initial medical presentation of the novel coronavirus disease 2019 (COVID-19), Canadian Journal of Ophthalmology (2020). DOI: 10.1016/j.jcjo.2020.03.003
http://dx.doi.org/10.1016/j.jcjo.2020.03.003

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Ok, so this may seem a non-invasive testing method for SARS-CoV-2, @jtd

I remembered the following discussion on similar topic from another post, during our initial discussion @vvcstemplay talking about

Interestingly, there is another story also inside this. The patient’s worsening red eye and repeated visits to ophtalmolgoists and negative testing of typical eye tests did not lead to a decision to test for SARS-CoV-2. It was a decision governed by the non-healthcare body, as their testing recommendations expanded for geographical locations (and the patient had an expanded travel history). It was only then the health care authorities decided to do the NP swab test and then it was positive for SARS-CoV-2. This is also a case study for how the testing recommendations change and therefore the number of positive cases spike up.

Nevertheless, repeated results, or rather repeated findings of such symptons easily visible to naked eye can confirm to use this as detection method of coronavirus. (Although in this case also it is about the red eye and watery discharge cases). An eye for an eye!

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A non invasive quick test for Covid-19 has been identified, it is claimed, from Israel.

Rather than chemical or spectroscopic analysis, it uses resonant frequencies. The virus, it turns out, has a structure that resonates at a singular frequency, which is quickly and easily picked up by an appropriate smart sensor. Not sure why the sensor needs to be smart, as such, but the report indicates that this helps.

Or maybe it’s not smart so much as finely tuned, since the frequency is in the GHz range, and ordinary sensors would be easily disturbed by ambient temperature etc.

And coming back to the thought that inspired this thread, a general rapid testing device for all viruses might be the next step, since they are probably characterised by unique structures.

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Vow. this is really useful.

I think someone may have seen our discussion that we were talking about a breath analyzer kind of non-invasive testing method :grinning: :smiley:

Blockquote Interesting discussions @vvcstemplay @jtd. Now that sniffing the biomarkers of volatile organic compounds by dogs is being studied. Then how about a device like a breath analyzer for non-invasive testing. It works for testing drunk driving

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This is just fantastic. If a virus has a specific unique resonant frequency, generating that frequency and stimulating a sample will cause the source to get attenuated. By comparing our emitted amplitude with and without sample it would be possible to deduce the presence and most likely even the quantity of viri.
By shifting the frequency - also known as sweeping - one could test for a very large number of unique viri. The caveat would be that the number of viri will determine how sophisticated the equipment has to be.

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The frequency of resonance is in the terahertz region. Producing these waves in an uncontrolled way is easy - Peeling cello tape off it’s roll generates terahertz radiation. But controlled emission, detection and measurement is extremely hard.
So the equipment is probably a long way off from deployment and very expensive.

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Here’s where some borrowing from the field of audible acoustics might be helpful. While nearly all higher frequencies of audible sound cannot be sensed by most humans past the age of 40 or so, they are provably well qualified to differentiate between a good quality and bad quality music performance, from the right use of musical instruments to the ambient sound quality of the listening hall.

How is this possible? One answer is that even an age-deteriorated binaural hearing sense differentiates between the audio impulses arriving from different sides of the listening area, at different times, thanks to the length of bounces from the direct instrument via the walls, ceiling and rear.

The mind then assembles all these complex sounds, and quickly (this is acoustics, so it’s not exactly at supersonic speeds) generates a composite signal that is compared with memories of excellent acoustic experiences from the past, and a rating awarded, internally, although the actual frequencies can no longer be sensed.

One can conceptualise an analogue to this, where the terahertz reflections from the virus crystal are assessed in terms of much lower, and easier to sense reliably, resonant frequencies.

I’m not very familiar with radio telescopes, but it is quite obvious that these kind of problems have long been solved for star measurements, even at really high frequencies.

Since a healthcare testing gadget does not have to solve random problems of the universe, but only some specific known issues, whose parameters can be stored in a lookup table, I’m guessing that a test device can actually be made relatively inexpensively.

Not suggesting it can be done overnight either, but that it is achievable.

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Abstract

Objective To determine the diagnostic accuracy of serological tests for coronavirus disease-2019 (covid-19).

Design Systematic review and meta-analysis.

Data sources Medline, bioRxiv, and medRxiv from 1 January to 30 April 2020, using subject headings or subheadings combined with text words for the concepts of covid-19 and serological tests for covid-19.

Eligibility criteria and data analysis Eligible studies measured sensitivity or specificity, or both of a covid-19 serological test compared with a reference standard of viral culture or reverse transcriptase polymerase chain reaction. Studies were excluded with fewer than five participants or samples. Risk of bias was assessed using quality assessment of diagnostic accuracy studies 2 (QUADAS-2). Pooled sensitivity and specificity were estimated using random effects bivariate meta-analyses.

Main outcome measures The primary outcome was overall sensitivity and specificity, stratified by method of serological testing (enzyme linked immunosorbent assays (ELISAs), lateral flow immunoassays (LFIAs), or chemiluminescent immunoassays (CLIAs)) and immunoglobulin class (IgG, IgM, or both). Secondary outcomes were stratum specific sensitivity and specificity within subgroups defined by study or participant characteristics, including time since symptom onset.

Results 5016 references were identified and 40 studies included. 49 risk of bias assessments were carried out (one for each population and method evaluated). High risk of patient selection bias was found in 98% (48/49) of assessments and high or unclear risk of bias from performance or interpretation of the serological test in 73% (36/49). Only 10% (4/40) of studies included outpatients. Only two studies evaluated tests at the point of care. For each method of testing, pooled sensitivity and specificity were not associated with the immunoglobulin class measured. The pooled sensitivity of ELISAs measuring IgG or IgM was 84.3% (95% confidence interval 75.6% to 90.9%), of LFIAs was 66.0% (49.3% to 79.3%), and of CLIAs was 97.8% (46.2% to 100%). In all analyses, pooled sensitivity was lower for LFIAs, the potential point-of-care method. Pooled specificities ranged from 96.6% to 99.7%. Of the samples used for estimating specificity, 83% (10 465/12 547) were from populations tested before the epidemic or not suspected of having covid-19. Among LFIAs, pooled sensitivity of commercial kits (65.0%, 49.0% to 78.2%) was lower than that of non-commercial tests (88.2%, 83.6% to 91.3%). Heterogeneity was seen in all analyses. Sensitivity was higher at least three weeks after symptom onset (ranging from 69.9% to 98.9%) compared with within the first week (from 13.4% to 50.3%).
https://www.bmj.com/content/370/bmj.m2516

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Abstract

Coronavirus disease 2019 (COVID-19) is a newly emerging human infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, previously called 2019-nCoV). Based on the rapid increase in the rate of human infection, the World Health Organization (WHO) has classified the COVID-19 outbreak as a pandemic. Because no specific drugs or vaccines for COVID-19 are yet available, early diagnosis and management are crucial for containing the outbreak. Here, we report a field-effect transistor (FET)-based biosensing device for detecting SARS-CoV-2 in clinical samples. The sensor was produced by coating graphene sheets of the FET with a specific antibody against SARS-CoV-2 spike protein. The performance of the sensor was determined using antigen protein, cultured virus, and nasopharyngeal swab specimens from COVID-19 patients. Our FET device could detect the SARS-CoV-2 spike protein at concentrations of 1 fg/mL in phosphate-buffered saline and 100 fg/mL clinical transport medium. In addition, the FET sensor successfully detected SARS-CoV-2 in culture medium (limit of detection [LOD]: 1.6 × 101 pfu/mL) and clinical samples (LOD: 2.42 × 102 copies/mL). Thus, we have successfully fabricated a promising FET biosensor for SARS-CoV-2; our device is a highly sensitive immunological diagnostic method for COVID-19 that requires no sample pretreatment or labeling.
https://pubs.acs.org/doi/full/10.1021/acsnano.0c02823

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Rapid Gel Card Agglutination Assays for Serological Analysis Following SARS-CoV-2 Infection in Humans

https://pubs.acs.org/doi/10.1021/acssensors.0c01050

Abstract

Abstract Image

High-throughput and rapid serology assays to detect the antibody response specific to severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) in human blood samples are urgently required to improve our understanding of the effects of COVID-19 across the world. Short-term applications include rapid case identification and contact tracing to limit viral spread, while population screening to determine the extent of viral infection across communities is a longer-term need. Assays developed to address these needs should match the ASSURED criteria. We have identified agglutination tests based on the commonly employed blood typing methods as a viable option. These blood typing tests are employed in hospitals worldwide, are high-throughput, fast (10–30 min), and automated in most cases. Herein, we describe the application of agglutination assays to SARS-CoV-2 serology testing by combining column agglutination testing with peptide–antibody bioconjugates, which facilitate red cell cross-linking only in the presence of plasma containing antibodies against SARS-CoV-2. This simple, rapid, and easily scalable approach has immediate application in SARS-CoV-2 serological testing and is a useful platform for assay development beyond the COVID-19 pandemic.

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oh,wow! thanks for this paper.

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@jtd thanks for suggesting these interesting papers. I have suggested some of these for blurb writing for CovidGyan – Research Perspectives. The team can decide and assign the task to any one interested or willing to write.

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